diff --git a/Cargo.toml b/Cargo.toml
index 09f2db5..cbbbc8b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,7 +23,8 @@ keywords = [
 license = "MIT OR APACHE-2.0"
 readme = "README.md"
 repository = "https://github.com/rustfoundation/overloading-examples"
-# Requires #[splat] which was introduced just before 1.99 branched
+# Requires #[rustc_splat] which was renamed in nightly-2026-07-31 (rust-lang/rust#159817)
+# FIXME: we can't specify nightly dates or the latest nightly here, update to 1.100 once 1.99 beta branches (20 August 2026)
 rust-version = "1.99"
 
 [workspace.dependencies]
diff --git a/cpp-hypot-overload/src/bin/cpp-hypot-overload.rs b/cpp-hypot-overload/src/bin/cpp-hypot-overload.rs
index f6e3b5e..744dffa 100644
--- a/cpp-hypot-overload/src/bin/cpp-hypot-overload.rs
+++ b/cpp-hypot-overload/src/bin/cpp-hypot-overload.rs
@@ -17,7 +17,7 @@ trait HypotArgs: Tuple {
 }
 
 /// Calls the overloaded C++ `std::hypot` function with the given arguments.
-fn hypot<Args: HypotArgs>(#[splat] args: Args) -> <Args as HypotArgs>::Output {
+fn hypot<Args: HypotArgs>(#[rustc_splat] args: Args) -> <Args as HypotArgs>::Output {
     args.call_hypot()
 }
 
diff --git a/cpp-hypot-overload/src/bin/rust-hypot-overload.rs b/cpp-hypot-overload/src/bin/rust-hypot-overload.rs
index 444e102..b502619 100644
--- a/cpp-hypot-overload/src/bin/rust-hypot-overload.rs
+++ b/cpp-hypot-overload/src/bin/rust-hypot-overload.rs
@@ -11,7 +11,7 @@ trait HypotArgs: Tuple {
 }
 
 /// Calls the overloaded Rust `hypot` function with the given arguments.
-fn hypot<Args: HypotArgs>(#[splat] args: Args) -> <Args as HypotArgs>::Output {
+fn hypot<Args: HypotArgs>(#[rustc_splat] args: Args) -> <Args as HypotArgs>::Output {
     args.call_hypot()
 }